CHAOTIC TRAJECTORIES IN STEADY THERMALLY DRIVEN STOKES FLOWS

Chaos of trajectories of fluid particles for a stationary Stokes flow within a sphere is considered. The flow is a linear superposition of t wo flows, the first one being buoyancy driven and the second one being a solid body rotation. Both flows, alone, would induce closed traject ories. Using Poincare sections, we study chaos generated by the combin ation flow for different values of the ratio between the amplitudes of the superimposed flows. We show, although the two flows are topologic ally merely different that global chaos is reached for a ratio of the amplitudes of order unity.